We've heard it all before. I sat in the front row at Ballmer's CES 2010 keynote in January, on the eve of Apple's iPad announcement, when Ballmer tried to preempt Steve Jobs by announcing Windows 7 "Slate PCs" that would be released during 2010.

While the iPad has turned into an international phenomenon, Ballmer's promise turned out to be little more than vaporware. No Windows 7 tablets have hit the market, or even been officially announced.

Ballmer showing off an old pen-based Tablet PC. Photo credit: CNET

The flagship slate PC from Hewlett-Packard that Ballmer showed off at CES got cancelled by HP because Windows 7 was reportedly too much of a power hog. ASUS, which had been planning to power its Eee Pad with Windows, switched horses and went with Android instead. And, one of Microsoft's most reliable partners, Dell, also spurned Windows for Android on its tablet — the Dell Streak.

You can't blame these traditional Microsoft partners for balking at Windows 7 on their tablets. After all, Microsoft has treated these devices as just another form factor of the PC, and Microsoft saw the biggest advantage of Windows 7 tablets being that they had all the power and capabilities of a full PC. That was a fundamentally misguided approach.

The iPad and the forthcoming Android tablets are much more like smartphones than PCs, and users tend to like these devices for two reasons:

The touch-based interface is far more self-evident than a traditional PC or Mac

The app experience provides single-task immersion that makes it easy to do things

You simply can't recreate those two factors in a tablet with a full PC operating system. It's too complicated. A few people inside Microsoft recognized that and they trumpeted Windows Embedded Compact 7 (based on the old Windows CE) as an answer for a Microsoft-powered tablet computer that could match the capabilities and user experience of Android and iPhone.

But, that naturally confused everyone. After all, Ballmer had already declared the full Windows 7 as Microsoft's tablet platform in January. And, in February, Microsoft unveiled Windows Phone 7 as the company's next smartphone platform, setting off speculation that it could also become the natural candidate for a Microsoft tablet.

Microsoft did little to help clear up the confusion. In fact, the company said that it would "continue to support, ship and sell [Windows Mobile] 6.5" even after the incompatible Windows Phone 7 devices arrived. And, this spring the company also released the ill-fated Kin smartphone, which was based on an entirely different mobile platform altogether and which was so poorly received in the market place that Microsoft and Verizon killed it less than two months after launching it.

So Microsoft has talked about five different mobile platforms in 2010: Windows Mobile 6.5, Windows Embedded Compact 7, Windows Phone 7, Kin, and Windows 7, with very little explanation about how these platforms relate to each other and which ones Microsoft wants to use in which settings. Is it any surprise then that Microsoft is flailing so badly in the mobile space and has no coherent tablet strategy?

And I think it's fair to say that Microsoft's tablet troubles are indicative of the larger problems that are haunting today's Microsoft — similar teams competing for resources, minimal collaboration between similar projects, and not enough vision from the top to get everyone pushing in the same direction.

What's puzzling is that Ballmer and the Microsoft board of directors haven't come under greater fire for this lack of product focus, and for the misguided strategies that have led to Microsoft falling so far behind in the mobile computing race, which will likely end up spreading to far more people around the globe than the PC revolution.

This failure is a direct consequence of Microsoft putting an accountant in the CEO position to succeed Bill Gates. Steve Ballmer has done an excellent job of maximizing Microsoft's profits and milking as much money as possible out of consumers and businesses for Microsoft products — primarily Windows and Office. But, Ballmer has done little to propel the company forward technologically or strategically.

That's why Wall Street has continued to bet against Microsoft. The stock market is a barometer of the expectations of a company's future success. Microsoft's stock price has hovered in virtually the same place for a decade because Ballmer's leadership has given the market no reason to bet on Microsoft's future.

When you hear Ballmer speak, the stuff he gets most excited is things like explaining that Microsoft now has eight separate billion dollar businesses. Ballmer would make a great CFO or COO/President of Microsoft. He'd also be a great CEO of a mature public company trying to maximize its profits in order to produce a dividend for its shareholders.

However, Microsoft's top dog needs to be a product leader. If you look at all of today's successful tech companies, they almost all have a product visionary at or near the top of the org chart.

Microsoft still has plenty of strong assets and a ton of smart engineers in Redmond. But, where's the leadership? What's the company's vision of the future of computing? At a time when mobility is about to power the next great wave of expansion in the technology industry and bring the benefits of computing to hundreds of millions of new people, Microsoft is standing on the sidelines still trying to figure out which play to run.